首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   139403篇
  免费   7297篇
  国内免费   121篇
耳鼻咽喉   2296篇
儿科学   4764篇
妇产科学   3253篇
基础医学   20957篇
口腔科学   4576篇
临床医学   11572篇
内科学   25422篇
皮肤病学   4065篇
神经病学   14274篇
特种医学   6031篇
外科学   21370篇
综合类   630篇
一般理论   40篇
预防医学   7617篇
眼科学   3124篇
药学   9498篇
中国医学   209篇
肿瘤学   7123篇
  2023年   801篇
  2022年   480篇
  2021年   1274篇
  2020年   1191篇
  2019年   1456篇
  2018年   2997篇
  2017年   2556篇
  2016年   3317篇
  2015年   2860篇
  2014年   3153篇
  2013年   5574篇
  2012年   7123篇
  2011年   8013篇
  2010年   4554篇
  2009年   3057篇
  2008年   8107篇
  2007年   8565篇
  2006年   8276篇
  2005年   8178篇
  2004年   7670篇
  2003年   7739篇
  2002年   7634篇
  2001年   5380篇
  2000年   6810篇
  1999年   3805篇
  1998年   1489篇
  1997年   1242篇
  1996年   955篇
  1995年   797篇
  1994年   784篇
  1993年   743篇
  1992年   758篇
  1991年   659篇
  1990年   629篇
  1989年   660篇
  1988年   533篇
  1987年   629篇
  1986年   526篇
  1985年   719篇
  1984年   687篇
  1983年   582篇
  1982年   610篇
  1981年   584篇
  1980年   534篇
  1979年   511篇
  1978年   456篇
  1977年   506篇
  1976年   425篇
  1975年   427篇
  1974年   405篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Many environmental risk factors for hepatobiliary cancers are known but whether they are associated with specific cancer types is unclear. We present here a novel approach of assessing standardized incidence ratios (SIRs) of previously diagnosed comorbidities for hepatocellular carcinoma (HCC), gallbladder cancer (GBC), cholangiocarcinoma (CCA) and ampullary cancer. The 13 comorbidities included alcohol and nonalcohol related liver disease, chronic obstructive pulmonary disease, gallstone disease, viral and other kinds of hepatitis, infection of bile ducts, hepatic and other autoimmune diseases, obesity and diabetes. Patients were identified from the Swedish Inpatient Register from 1987 to 2018, and their cancers were followed from 1997 onwards. SIRs for HCC were 80 to 100 in men and women diagnosed with hepatitis C virus and they were also >10 in patients diagnosed with hepatitis B virus, other kind of hepatitis, hepatic autoimmune disease and nonalcohol related liver disease. Many of these risks, as well as alcohol related liver disease, were either specific to HCC or were shared with intrahepatic CCA. For GBC, CCA and ampullary cancer infection of bile ducts was the main risk factor. Gallstone disease, nonhepatic autoimmune diseases and diabetes were associated with all hepatobiliary cancers. The limitations of the study include inability to cover some rare risk factors and limited follow-up time. Many of the considered comorbidities are characterized by chronic inflammation and/or overt immune disturbance in autoimmune diseases. The results suggest that local chronic inflammation and a related immune disturbance is the carcinogenic trigger for all these cancers.  相似文献   
2.
3.
4.
5.
6.
The prospective, multicenter, noninterventional TACTIC study assessed effectiveness and safety of trifluridine/tipiracil (FTD/TPI) in patients with metastatic colorectal cancer (mCRC) in a real-world setting in Germany, thus evaluating the external validity of the findings from the pivotal RECOURSE trial. Primary endpoint was overall survival (OS). Secondary objectives included progression-free survival (PFS), safety, and quality of life (QoL). Subgroups comprised patients with good (<3 metastatic sites at inclusion, ≥18 months from diagnosis of first metastasis to inclusion) or poor (remaining patients) prognostic characteristics (GPC/PPC). GPC without liver metastases was considered best prognostic characteristics (BPC). In total, 307 eligible patients (pretreated or not suitable for other available therapies) were treated with FTD/TPI. Overall, median [95%-CI] OS was 7.4 months [6.4-8.6], median PFS was 2.9 months [2.8-3.3]. In BPC (n = 65) and GPC (n = 176) compared to PPC (n = 124) subgroup, median OS (13.3 [9.1-17.6] vs 8.9 [7.6-9.8] vs 5.1 [4.4-7.0] months) and median PFS (4.0 [3.3-5.3] vs 3.4 [3.0-3.7] vs 2.6 [2.4-2.8] months) were longer. Patient-reported QoL, assessed by validated questionnaires (EQ-5D-5L, PRO-CTCAE), was stable throughout FTD/TPI treatment. Predominant FTD/TPI-related adverse events of grades 3 or 4 were neutropenia (13.0%), leukopenia (7.5%), and anemia (5.2%). Altogether, palliative FTD/TPI therapy in patients with pretreated mCRC was associated with prolonged survival, delayed progression, maintained health-related QoL, and manageable toxicity. Low metastatic burden and indolent disease were favorable prognostic factors for survival. TACTIC confirms the effectiveness and safety of FTD/TPI, highlighting its value in routine clinical practice.  相似文献   
7.
Troppmair  Teresa  Egger  J.  Krösbacher  A.  Zanvettor  A.  Schinnerl  A.  Neumayr  A.  Baubin  M. 《Der Anaesthesist》2022,71(4):272-280
Die Anaesthesiologie - Die Qualität eines Rettungssystems zeichnet sich auch durch den effizienten Einsatz seiner personellen und Fahrzeugressourcen aus. So können im berechtigten Fall...  相似文献   
8.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Um Menschen eine informierte Entscheidung über die Teilnahme an Krebsfrüherkennungsuntersuchungen zu ermöglichen,...  相似文献   
9.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Das Hepatitis-E-Virus (HEV) ist ein Erreger einer akuten Hepatitis beim Menschen. Darüber hinaus treten zunehmend auch...  相似文献   
10.

Background

Weaning from mechanical ventilation and tracheostomy after prolonged intensive care consume enormous resources with optimal management not currently well described. Restoration of respiratory flow via the upper airway is essential and early cuff-deflation using a one-way valve (OWV) is recommended. However, extended OWV use may cause dry airways and thickened secretions which challenge the weaning process. High-flow therapy via the tracheostomy tube (HFT-T) humidifies inspired air and may be connected via an in-line OWV (HFT-T-OWV) alleviating these problems. We aim to provide clinical and experimental data on the safety of HFT-T-OWV along with a practical guide to facilitate clinical use during weaning from mechanical ventilation and tracheostomy.

Methods

Data on adverse events of HFT-T-OWV were retrieved from a quality register for patients treated at an intensive care rehabilitation center between 2019 and 2022. Benchtop experiments were performed to measure maximum pressures and pressure support generated by HFT-T-OWV at 25–60 L/min flow using two different HFT-T adapters (interfaces). In simulated airway obstruction using a standard OWV (not in-line) maximum pressures were measured with oxygen delivered via the side port at 1–3 L/min.

Results

Of 128 tracheostomized patients who underwent weaning attempts, 124 were treated with HFT-T-OWV. The therapy was well tolerated, and no adverse events related to the practice were detected. The main reason for not using HFT-T-OWV was partial upper airway obstruction using a OWV. Benchtop experiments demonstrated HFT-T-OWV maximum pressures <4 cmH2O and pressure support 0–0.6 cmH2O. In contrast, 1–3 L/min supplemental oxygen via a standard OWV caused pressures between 84 and 148 cmH2O during simulated airway obstruction.

Conclusions

Current study clinical data and benchtop experiments indicate that HFT-T-OWV was well tolerated and appeared safe. Pressure support was low, but humidification may enable extended use of a OWV without dry airway mucosa and thickened secretions. Results suggest the treatment could offer advantages to standard OWV use, with or without supplementary oxygen, as well as to HFT-T without a OWV, for weaning from mechanical ventilation and tracheostomy. However, for definitive treatment recommendations, randomized clinical trials are needed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号